Bulk cloud microphysical properties as seen from numerical simulation and remote sensing products: case study of a hailstorm event over La Plata basin

<p>Severe thunderstorms develop over La Plata basin, in southeastern South America, more&#160;often during austral wintertime, between June and August. These systems have significant&#160;socioeconomic impacts over the region, and, therefore, a better understanding of how&#160;atmospheric drivers modulate their formation is important to improve the forecast of such&#160;phenomena. In this study, we selected a hailstorm event observed over southeastern La Plata&#160;basin during 14-15 July 2016, and simulated it using three Brazilian developments on the&#160;Regional Atmospheric Modeling System (BRAMS) model configurations, each driven by a&#160;different global forcing: Global Forecast System (GFS), Climate Forecast System version 2&#160;(CFSv2), and ECMWF Reanalysis v5 (ERA5). The ability of the BRAMS model in&#160;simulating cloud microphysical properties was evaluated by comparing the model output with&#160;satellite- and radar-based observations. Model results showed good skill in capturing the basic&#160;characteristics of the thunderstorm in terms of the spatial distribution of hydrometeors. The&#160;location of the maximum concentrations of hydrometeors was realistically represented by all&#160;simulations; however, slight to moderate differences in cloud properties between observations&#160;and model simulations were observed, with BRAMS/CFSv2 and BRAMS/ERA5 simulations&#160;performing best and worst, respectively, against measurements. In addition, these two&#160;simulations were able to reproduce ground-level hail concentrations over some of the reported&#160;hail fall areas. This study provides a first assessment of the BRAMS model to reproduce&#160;microphysical features of a severe thunderstorm captured by remote sensing observations over&#160;southeastern La Plata basin, one of the most hail-damage prone areas in the world.</p>